coders/bmp.c

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%                            BBBB   M   M  PPPP                               %
%                            B   B  MM MM  P   P                              %
%                            BBBB   M M M  PPPP                               %
%                            B   B  M   M  P                                  %
%                            BBBB   M   M  P                                  %
%                                                                             %
%                                                                             %
%             Read/Write Microsoft Windows Bitmap Image Format                %
%                                                                             %
%                              Software Design                                %
%                                John Cristy                                  %
%                            Glenn Randers-Pehrson                            %
%                               December 2001                                 %
%                                                                             %
%                                                                             %
%  Copyright 1999-2010 ImageMagick Studio LLC, a non-profit organization      %
%  dedicated to making software imaging solutions freely available.           %
%                                                                             %
%  You may not use this file except in compliance with the License.  You may  %
%  obtain a copy of the License at                                            %
%                                                                             %
%    http://www.imagemagick.org/script/license.php                            %
%                                                                             %
%  Unless required by applicable law or agreed to in writing, software        %
%  distributed under the License is distributed on an "AS IS" BASIS,          %
%  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
%  See the License for the specific language governing permissions and        %
%  limitations under the License.                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
*/

/*
  Include declarations.
*/
#include "magick/studio.h"
#include "magick/blob.h"
#include "magick/blob-private.h"
#include "magick/cache.h"
#include "magick/colormap-private.h"
#include "magick/color-private.h"
#include "magick/colormap.h"
#include "magick/colorspace.h"
#include "magick/exception.h"
#include "magick/exception-private.h"
#include "magick/image.h"
#include "magick/image-private.h"
#include "magick/list.h"
#include "magick/log.h"
#include "magick/magick.h"
#include "magick/memory_.h"
#include "magick/monitor.h"
#include "magick/monitor-private.h"
#include "magick/profile.h"
#include "magick/quantum-private.h"
#include "magick/static.h"
#include "magick/string_.h"
#include "magick/module.h"
#include "magick/transform.h"

/*
  Macro definitions (from Windows wingdi.h).
*/
#undef BI_JPEG
#define BI_JPEG  4
#undef BI_PNG
#define BI_PNG  5
#if !defined(MAGICKCORE_WINDOWS_SUPPORT) || defined(__MINGW32__)
#define BI_RGB  0
#define BI_RLE8  1
#define BI_RLE4  2
#define BI_BITFIELDS  3

#define LCS_CALIBRATED_RBG  0
#define LCS_sRGB  1
#define LCS_WINDOWS_COLOR_SPACE  2
#define PROFILE_LINKED  3
#define PROFILE_EMBEDDED  4

#define LCS_GM_BUSINESS  1  /* Saturation */
#define LCS_GM_GRAPHICS  2  /* Relative */
#define LCS_GM_IMAGES  4  /* Perceptual */
#define LCS_GM_ABS_COLORIMETRIC  8  /* Absolute */
#endif

/*
  Typedef declarations.
*/
typedef struct _BMPInfo
{
  unsigned int
    file_size,
    ba_offset,
    offset_bits,
    size;

  ssize_t
    width,
    height;

  unsigned short
    planes,
    bits_per_pixel;

  unsigned int
    compression,
    image_size,
    x_pixels,
    y_pixels,
    number_colors,
    red_mask,
    green_mask,
    blue_mask,
    alpha_mask,
    colors_important;

  int
    colorspace;

  PrimaryInfo
    red_primary,
    green_primary,
    blue_primary,
    gamma_scale;
} BMPInfo;

/*
  Forward declarations.
*/
static MagickBooleanType
  WriteBMPImage(const ImageInfo *,Image *);

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   D e c o d e I m a g e                                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  DecodeImage unpacks the packed image pixels into runlength-encoded
%  pixel packets.
%
%  The format of the DecodeImage method is:
%
%      MagickBooleanType DecodeImage(Image *image,
%        const size_t compression,unsigned char *pixels)
%
%  A description of each parameter follows:
%
%    o image: the address of a structure of type Image.
%
%    o compression:  Zero means uncompressed.  A value of 1 means the
%      compressed pixels are runlength encoded for a 256-color bitmap.
%      A value of 2 means a 16-color bitmap.  A value of 3 means bitfields
%      encoding.
%
%    o pixels:  The address of a byte (8 bits) array of pixel data created by
%      the decoding process.
%
*/

static inline ssize_t MagickAbsoluteValue(const ssize_t x)
{
  if (x < 0)
    return(-x);
  return(x);
}

static inline size_t MagickMax(const size_t x,const size_t y)
{
  if (x > y)
    return(x);
  return(y);
}

static inline ssize_t MagickMin(const ssize_t x,const ssize_t y)
{
  if (x < y)
    return(x);
  return(y);
}

static MagickBooleanType DecodeImage(Image *image,
  const size_t compression,unsigned char *pixels)
{
  int
    count;

  ssize_t
    y;

  register ssize_t
    i,
    x;

  register unsigned char
    *p,
    *q;

  unsigned char
    byte;

  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  assert(pixels != (unsigned char *) NULL);
  (void) ResetMagickMemory(pixels,0,(size_t) image->columns*image->rows*
    sizeof(*pixels));
  byte=0;
  x=0;
  p=pixels;
  q=pixels+(size_t) image->columns*image->rows;
  for (y=0; y < (ssize_t) image->rows; )
  {
    if ((p < pixels) || (p >= q))
      break;
    count=ReadBlobByte(image);
    if (count == EOF)
      break;
    if (count != 0)
      {
        /*
          Encoded mode.
        */
        count=MagickMin(count,(int) (q-p));
        byte=(unsigned char) ReadBlobByte(image);
        if (compression == BI_RLE8)
          {
            for (i=0; i < count; i++)
              *p++=(unsigned char) byte;
          }
        else
          {
            for (i=0; i < count; i++)
              *p++=(unsigned char)
                ((i & 0x01) != 0 ? (byte & 0x0f) : ((byte >> 4) & 0x0f));
          }
        x+=count;
      }
    else
      {
        /*
          Escape mode.
        */
        count=ReadBlobByte(image);
        if (count == 0x01)
          return(MagickTrue);
        switch (count)
        {
          case 0x00:
          {
            /*
              End of line.
            */
            x=0;
            y++;
            p=pixels+y*image->columns;
            break;
          }
          case 0x02:
          {
            /*
              Delta mode.
            */
            x+=ReadBlobByte(image);
            y+=ReadBlobByte(image);
            p=pixels+y*image->columns+x;
            break;
          }
          default:
          {
            /*
              Absolute mode.
            */
            count=MagickMin(count,(int) (q-p));
            if (compression == BI_RLE8)
              for (i=0; i < count; i++)
                *p++=(unsigned char) ReadBlobByte(image);
            else
              for (i=0; i < count; i++)
              {
                if ((i & 0x01) == 0)
                  byte=(unsigned char) ReadBlobByte(image);
                *p++=(unsigned char)
                  ((i & 0x01) != 0 ? (byte & 0x0f) : ((byte >> 4) & 0x0f));
              }
            x+=count;
            /*
              Read pad byte.
            */
            if (compression == BI_RLE8)
              {
                if ((count & 0x01) != 0)
                  (void) ReadBlobByte(image);
              }
            else
              if (((count & 0x03) == 1) || ((count & 0x03) == 2))
                (void) ReadBlobByte(image);
            break;
          }
        }
      }
    if (SetImageProgress(image,LoadImageTag,y,image->rows) == MagickFalse)
      break;
  }
  (void) ReadBlobByte(image);  /* end of line */
  (void) ReadBlobByte(image);
  return(MagickTrue);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   E n c o d e I m a g e                                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  EncodeImage compresses pixels using a runlength encoded format.
%
%  The format of the EncodeImage method is:
%
%    static MagickBooleanType EncodeImage(Image *image,
%      const size_t bytes_per_line,const unsigned char *pixels,
%      unsigned char *compressed_pixels)
%
%  A description of each parameter follows:
%
%    o image:  The image.
%
%    o bytes_per_line: the number of bytes in a scanline of compressed pixels
%
%    o pixels:  The address of a byte (8 bits) array of pixel data created by
%      the compression process.
%
%    o compressed_pixels:  The address of a byte (8 bits) array of compressed
%      pixel data.
%
*/
static size_t EncodeImage(Image *image,const size_t bytes_per_line,
  const unsigned char *pixels,unsigned char *compressed_pixels)
{
  ssize_t
    y;

  MagickBooleanType
    status;

  register const unsigned char
    *p;

  register ssize_t
    i,
    x;

  register unsigned char
    *q;

  /*
    Runlength encode pixels.
  */
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  assert(pixels != (const unsigned char *) NULL);
  assert(compressed_pixels != (unsigned char *) NULL);
  p=pixels;
  q=compressed_pixels;
  i=0;
  for (y=0; y < (ssize_t) image->rows; y++)
  {
    for (x=0; x < (ssize_t) bytes_per_line; x+=i)
    {
      /*
        Determine runlength.
      */
      for (i=1; ((x+i) < (ssize_t) bytes_per_line); i++)
        if ((i == 255) || (*(p+i) != *p))
          break;
      *q++=(unsigned char) i;
      *q++=(*p);
      p+=i;
    }
    /*
      End of line.
    */
    *q++=(unsigned char) 0x00;
    *q++=(unsigned char) 0x00;
    status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
                image->rows);
    if (status == MagickFalse)
      break;
  }
  /*
    End of bitmap.
  */
  *q++=(unsigned char) 0x00;
  *q++=(unsigned char) 0x01;
  return((size_t) (q-compressed_pixels));
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   I s B M P                                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  IsBMP() returns MagickTrue if the image format type, identified by the
%  magick string, is BMP.
%
%  The format of the IsBMP method is:
%
%      MagickBooleanType IsBMP(const unsigned char *magick,const size_t length)
%
%  A description of each parameter follows:
%
%    o magick: compare image format pattern against these bytes.
%
%    o length: Specifies the length of the magick string.
%
*/
static MagickBooleanType IsBMP(const unsigned char *magick,const size_t length)
{
  if (length < 2)
    return(MagickFalse);
  if ((LocaleNCompare((char *) magick,"BA",2) == 0) ||
      (LocaleNCompare((char *) magick,"BM",2) == 0) ||
      (LocaleNCompare((char *) magick,"IC",2) == 0) ||
      (LocaleNCompare((char *) magick,"PI",2) == 0) ||
      (LocaleNCompare((char *) magick,"CI",2) == 0) ||
      (LocaleNCompare((char *) magick,"CP",2) == 0))
    return(MagickTrue);
  return(MagickFalse);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e a d B M P I m a g e                                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ReadBMPImage() reads a Microsoft Windows bitmap image file, Version
%  2, 3 (for Windows or NT), or 4, and  returns it.  It allocates the memory
%  necessary for the new Image structure and returns a pointer to the new
%  image.
%
%  The format of the ReadBMPImage method is:
%
%      image=ReadBMPImage(image_info)
%
%  A description of each parameter follows:
%
%    o image_info: the image info.
%
%    o exception: return any errors or warnings in this structure.
%
*/

static Image *ReadBMPImage(const ImageInfo *image_info,ExceptionInfo *exception)
{
  BMPInfo
    bmp_info;

  Image
    *image;

  IndexPacket
    index;

  ssize_t
    y;

  MagickBooleanType
    status;

  MagickOffsetType
    offset,
    start_position;

  register IndexPacket
    *indexes;

  register ssize_t
    x;

  register PixelPacket
    *q;

  register ssize_t
    i;

  register unsigned char
    *p;

  ssize_t
    count;

  size_t
    length;

  unsigned char
    magick[12],
    *pixels;

  size_t
    bit,
    blue,
    bytes_per_line,
    green,
    opacity,
    red;

  /*
    Open image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  if (image_info->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
      image_info->filename);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickSignature);
  image=AcquireImage(image_info);
  status=OpenBlob(image_info,image,ReadBinaryBlobMode,exception);
  if (status == MagickFalse)
    {
      image=DestroyImageList(image);
      return((Image *) NULL);
    }
  /*
    Determine if this a BMP file.
  */
  (void) ResetMagickMemory(&bmp_info,0,sizeof(bmp_info));
  bmp_info.ba_offset=0;
  start_position=0;
  count=ReadBlob(image,2,magick);
  do
  {
    LongPixelPacket
      shift;

    PixelPacket
      quantum_bits;

    size_t
      profile_data,
      profile_size;

    /*
      Verify BMP identifier.
    */
    if (bmp_info.ba_offset == 0)
      start_position=TellBlob(image)-2;
    bmp_info.ba_offset=0;
    while (LocaleNCompare((char *) magick,"BA",2) == 0)
    {
      bmp_info.file_size=ReadBlobLSBLong(image);
      bmp_info.ba_offset=ReadBlobLSBLong(image);
      bmp_info.offset_bits=ReadBlobLSBLong(image);
      count=ReadBlob(image,2,magick);
      if (count != 2)
        break;
    }
    if (image->debug != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),"  Magick: %c%c",
        magick[0],magick[1]);
    if ((count == 0) || ((LocaleNCompare((char *) magick,"BM",2) != 0) &&
        (LocaleNCompare((char *) magick,"CI",2) != 0)))
      ThrowReaderException(CorruptImageError,"ImproperImageHeader");
    bmp_info.file_size=ReadBlobLSBLong(image);
    (void) ReadBlobLSBLong(image);
    bmp_info.offset_bits=ReadBlobLSBLong(image);
    bmp_info.size=ReadBlobLSBLong(image);
    if (image->debug != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),"  BMP size: %u",
        bmp_info.size);
    if (bmp_info.size == 12)
      {
        /*
          OS/2 BMP image file.
        */
        bmp_info.width=(short) ReadBlobLSBShort(image);
        bmp_info.height=(short) ReadBlobLSBShort(image);
        bmp_info.planes=ReadBlobLSBShort(image);
        bmp_info.bits_per_pixel=ReadBlobLSBShort(image);
        bmp_info.x_pixels=0;
        bmp_info.y_pixels=0;
        bmp_info.number_colors=0;
        bmp_info.compression=BI_RGB;
        bmp_info.image_size=0;
        bmp_info.alpha_mask=0;
        if (image->debug != MagickFalse)
          {
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Format: OS/2 Bitmap");
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Geometry: %.20gx%.20g",(double) bmp_info.width,(double)
              bmp_info.height);
          }
      }
    else
      {
        /*
          Microsoft Windows BMP image file.
        */
        if (bmp_info.size < 40)
          ThrowReaderException(CorruptImageError,"NonOS2HeaderSizeError");
        bmp_info.width=(int) ReadBlobLSBLong(image);
        bmp_info.height=(int) ReadBlobLSBLong(image);
        bmp_info.planes=ReadBlobLSBShort(image);
        bmp_info.bits_per_pixel=ReadBlobLSBShort(image);
        bmp_info.compression=ReadBlobLSBLong(image);
        bmp_info.image_size=ReadBlobLSBLong(image);
        bmp_info.x_pixels=ReadBlobLSBLong(image);
        bmp_info.y_pixels=ReadBlobLSBLong(image);
        bmp_info.number_colors=ReadBlobLSBLong(image);
        bmp_info.colors_important=ReadBlobLSBLong(image);
        profile_data=0;
        profile_size=0;
        if (image->debug != MagickFalse)
          {
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Format: MS Windows bitmap");
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Geometry: %.20gx%.20g",(double) bmp_info.width,(double)
              bmp_info.height);
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Bits per pixel: %.20g",(double) bmp_info.bits_per_pixel);
            switch ((int) bmp_info.compression)
            {
              case BI_RGB:
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Compression: BI_RGB");
                break;
              }
              case BI_RLE4:
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Compression: BI_RLE4");
                break;
              }
              case BI_RLE8:
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Compression: BI_RLE8");
                break;
              }
              case BI_BITFIELDS:
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Compression: BI_BITFIELDS");
                break;
              }
              case BI_PNG:
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Compression: BI_PNG");
                break;
              }
              case BI_JPEG:
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Compression: BI_JPEG");
                break;
              }
              default:
              {
                (void) LogMagickEvent(CoderEvent,GetMagickModule(),
                  "  Compression: UNKNOWN (%u)",bmp_info.compression);
              }
            }
            (void) LogMagickEvent(CoderEvent,GetMagickModule(),
              "  Number of colors: %u",bmp_info.number_colors);
          }
        bmp_info.red_mask=ReadBlobLSBLong(image);
        bmp_info.green_mask=ReadBlobLSBLong(image);
        bmp_info.blue_mask=ReadBlobLSBLong(image);
        if (bmp_info.size > 40)
          {
            double
              sum;

            /*
              Read color management information.
            */
            bmp_info.alpha_mask=ReadBlobLSBLong(image);
            bmp_info.colorspace=(int) ReadBlobLSBLong(image);
            /*
              Decode 2^30 fixed point formatted CIE primaries.
            */
            bmp_info.red_primary.x=(double) ReadBlobLSBLong(image)/0x3ffffff;
            bmp_info.red_primary.y=(double) ReadBlobLSBLong(image)/0x3ffffff;
            bmp_info.red_primary.z=(double) ReadBlobLSBLong(image)/0x3ffffff;
            bmp_info.green_primary.x=(double) ReadBlobLSBLong(image)/0x3ffffff;
            bmp_info.green_primary.y=(double) ReadBlobLSBLong(image)/0x3ffffff;
            bmp_info.green_primary.z=(double) ReadBlobLSBLong(image)/0x3ffffff;
            bmp_info.blue_primary.x=(double) ReadBlobLSBLong(image)/0x3ffffff;
            bmp_info.blue_primary.y=(double) ReadBlobLSBLong(image)/0x3ffffff;
            bmp_info.blue_primary.z=(double) ReadBlobLSBLong(image)/0x3ffffff;
            sum=bmp_info.red_primary.x+bmp_info.red_primary.y+
              bmp_info.red_primary.z;
            image->chromaticity.red_primary.x/=sum;
            image->chromaticity.red_primary.y/=sum;
            sum=bmp_info.green_primary.x+bmp_info.green_primary.y+
              bmp_info.green_primary.z;
            image->chromaticity.green_primary.x/=sum;
            image->chromaticity.green_primary.y/=sum;
            sum=bmp_info.blue_primary.x+bmp_info.blue_primary.y+
              bmp_info.blue_primary.z;
            image->chromaticity.blue_primary.x/=sum;
            image->chromaticity.blue_primary.y/=sum;
            /*
              Decode 16^16 fixed point formatted gamma_scales.
            */
            bmp_info.gamma_scale.x=(double) ReadBlobLSBLong(image)/0xffff;
            bmp_info.gamma_scale.y=(double) ReadBlobLSBLong(image)/0xffff;
            bmp_info.gamma_scale.z=(double) ReadBlobLSBLong(image)/0xffff;
            /*
              Compute a single gamma from the BMP 3-channel gamma.
            */
            image->gamma=(bmp_info.gamma_scale.x+bmp_info.gamma_scale.y+
              bmp_info.gamma_scale.z)/3.0;
          }
        if (bmp_info.size > 108)
          {
            size_t
              intent;

            /*
              Read BMP Version 5 color management information.
            */
            intent=ReadBlobLSBLong(image);
            switch ((int) intent)
            {
              case LCS_GM_BUSINESS:
              {
                image->rendering_intent=SaturationIntent;
                break;
              }
              case LCS_GM_GRAPHICS:
              {
                image->rendering_intent=RelativeIntent;
                break;
              }
              case LCS_GM_IMAGES:
              {
                image->rendering_intent=PerceptualIntent;
                break;
              }
              case LCS_GM_ABS_COLORIMETRIC:
              {
                image->rendering_intent=AbsoluteIntent;
                break;
              }
            }
            profile_data=ReadBlobLSBLong(image);
            profile_size=ReadBlobLSBLong(image);
            (void) ReadBlobLSBLong(image);  /* Reserved byte */
          }
      }
    if ((bmp_info.compression != BI_RGB) &&
        ((MagickSizeType) bmp_info.file_size != GetBlobSize(image)))
      (void) ThrowMagickException(exception,GetMagickModule(),CorruptImageError,
        "LengthAndFilesizeDoNotMatch","`%s'",image->filename);
    if (bmp_info.width <= 0)
      ThrowReaderException(CorruptImageError,"NegativeOrZeroImageSize");
    if (bmp_info.height == 0)
      ThrowReaderException(CorruptImageError,"NegativeOrZeroImageSize");
    if (bmp_info.planes != 1)
      ThrowReaderException(CorruptImageError,"StaticPlanesValueNotEqualToOne");
    if ((bmp_info.bits_per_pixel != 1) && (bmp_info.bits_per_pixel != 4) &&
        (bmp_info.bits_per_pixel != 8) && (bmp_info.bits_per_pixel != 16) &&
        (bmp_info.bits_per_pixel != 24) && (bmp_info.bits_per_pixel != 32))
      ThrowReaderException(CorruptImageError,"UnrecognizedBitsPerPixel");
    if (bmp_info.number_colors > (1U << bmp_info.bits_per_pixel))
      {
        if (bmp_info.bits_per_pixel < 24)
          ThrowReaderException(CorruptImageError,"UnrecognizedNumberOfColors");
        bmp_info.number_colors=0;
      }
    if ((bmp_info.compression == 1) && (bmp_info.bits_per_pixel != 8))
      ThrowReaderException(CorruptImageError,"UnrecognizedBitsPerPixel");
    if ((bmp_info.compression == 2) && (bmp_info.bits_per_pixel != 4))
      ThrowReaderException(CorruptImageError,"UnrecognizedBitsPerPixel");
    if ((bmp_info.compression == 3) && (bmp_info.bits_per_pixel < 16))
      ThrowReaderException(CorruptImageError,"UnrecognizedBitsPerPixel");
    switch (bmp_info.compression)
    {
      case BI_RGB:
      case BI_RLE8:
      case BI_RLE4:
      case BI_BITFIELDS:
        break;
      case BI_JPEG:
        ThrowReaderException(CoderError,"JPEGCompressNotSupported");
      case BI_PNG:
        ThrowReaderException(CoderError,"PNGCompressNotSupported");
      default:
        ThrowReaderException(CorruptImageError,"UnrecognizedImageCompression");
    }
    image->columns=(size_t) MagickAbsoluteValue(bmp_info.width);
    image->rows=(size_t) MagickAbsoluteValue(bmp_info.height);
    image->depth=bmp_info.bits_per_pixel <= 8 ? bmp_info.bits_per_pixel : 8;
    if ((bmp_info.bits_per_pixel == 16) ||
        (bmp_info.bits_per_pixel == 32))
      image->matte=bmp_info.alpha_mask != 0 ? MagickTrue : MagickFalse;
    if ((bmp_info.number_colors != 0) || (bmp_info.bits_per_pixel < 16))
      {
        size_t
          one;

        image->storage_class=PseudoClass;
        image->colors=bmp_info.number_colors;
        one=1;
        if (image->colors == 0)
          image->colors=one << bmp_info.bits_per_pixel;
      }
    if (image->storage_class == PseudoClass)
      {
        unsigned char
          *bmp_colormap;

        size_t
          packet_size;

        /*
          Read BMP raster colormap.
        */
        if (image->debug != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Reading colormap of %.20g colors",(double) image->colors);
        if (AcquireImageColormap(image,image->colors) == MagickFalse)
          ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
        bmp_colormap=(unsigned char *) AcquireQuantumMemory((size_t)
          image->colors,4*sizeof(*bmp_colormap));
        if (bmp_colormap == (unsigned char *) NULL)
          ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
        if ((bmp_info.size == 12) || (bmp_info.size == 64))
          packet_size=3;
        else
          packet_size=4;
        offset=SeekBlob(image,start_position+14+bmp_info.size,SEEK_SET);
        if (offset < 0)
          ThrowReaderException(CorruptImageError,"ImproperImageHeader");
        count=ReadBlob(image,packet_size*image->colors,bmp_colormap);
        if (count != (ssize_t) (packet_size*image->colors))
          ThrowReaderException(CorruptImageError,"InsufficientImageDataInFile");
        p=bmp_colormap;
        for (i=0; i < (ssize_t) image->colors; i++)
        {
          image->colormap[i].blue=ScaleCharToQuantum(*p++);
          image->colormap[i].green=ScaleCharToQuantum(*p++);
          image->colormap[i].red=ScaleCharToQuantum(*p++);
          if (packet_size == 4)
            p++;
        }
        bmp_colormap=(unsigned char *) RelinquishMagickMemory(bmp_colormap);
      }
    if ((image_info->ping != MagickFalse) && (image_info->number_scenes != 0))
      if (image->scene >= (image_info->scene+image_info->number_scenes-1))
        break;
    /*
      Read image data.
    */
    offset=SeekBlob(image,start_position+bmp_info.offset_bits,SEEK_SET);
    if (offset < 0)
      ThrowReaderException(CorruptImageError,"ImproperImageHeader");
    if (bmp_info.compression == BI_RLE4)
      bmp_info.bits_per_pixel<<=1;
    bytes_per_line=4*((image->columns*bmp_info.bits_per_pixel+31)/32);
    length=(size_t) bytes_per_line*image->rows;
    pixels=(unsigned char *) AcquireQuantumMemory((size_t) image->rows,
      MagickMax(bytes_per_line,image->columns+256UL)*sizeof(*pixels));
    if (pixels == (unsigned char *) NULL)
      ThrowReaderException(ResourceLimitError,"MemoryAllocationFailed");
    if ((bmp_info.compression == BI_RGB) ||
        (bmp_info.compression == BI_BITFIELDS))
      {
        if (image->debug != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Reading pixels (%.20g bytes)",(double) length);
        count=ReadBlob(image,length,pixels);
        if (count != (ssize_t) length)
          {
            pixels=(unsigned char *) RelinquishMagickMemory(pixels);
            ThrowReaderException(CorruptImageError,
              "InsufficientImageDataInFile");
          }
      }
    else
      {
        /*
          Convert run-length encoded raster pixels.
        */
        status=DecodeImage(image,bmp_info.compression,pixels);
        if (status == MagickFalse)
          {
            pixels=(unsigned char *) RelinquishMagickMemory(pixels);
            ThrowReaderException(CorruptImageError,
              "UnableToRunlengthDecodeImage");
          }
      }
    /*
      Initialize image structure.
    */
    image->x_resolution=(double) bmp_info.x_pixels/100.0;
    image->y_resolution=(double) bmp_info.y_pixels/100.0;
    image->units=PixelsPerCentimeterResolution;
    /*
      Convert BMP raster image to pixel packets.
    */
    if (bmp_info.compression == BI_RGB)
      {
        bmp_info.alpha_mask=0;
        bmp_info.red_mask=0x00ff0000U;
        bmp_info.green_mask=0x0000ff00U;
        bmp_info.blue_mask=0x000000ffU;
        if (bmp_info.bits_per_pixel == 16)
          {
            /*
              RGB555.
            */
            bmp_info.red_mask=0x00007c00U;
            bmp_info.green_mask=0x000003e0U;
            bmp_info.blue_mask=0x0000001fU;
          }
      }
    if ((bmp_info.bits_per_pixel == 16) || (bmp_info.bits_per_pixel == 32))
      {
        register size_t
          sample;

        /*
          Get shift and quantum bits info from bitfield masks.
        */
        (void) ResetMagickMemory(&shift,0,sizeof(shift));
        (void) ResetMagickMemory(&quantum_bits,0,sizeof(quantum_bits));
        if (bmp_info.red_mask != 0)
          while (((bmp_info.red_mask << shift.red) & 0x80000000UL) == 0)
            shift.red++;
        if (bmp_info.green_mask != 0)
          while (((bmp_info.green_mask << shift.green) & 0x80000000UL) == 0)
            shift.green++;
        if (bmp_info.blue_mask != 0)
          while (((bmp_info.blue_mask << shift.blue) & 0x80000000UL) == 0)
            shift.blue++;
        if (bmp_info.alpha_mask != 0)
          while (((bmp_info.alpha_mask << shift.opacity) & 0x80000000UL) == 0)
            shift.opacity++;
        sample=shift.red;
        while (((bmp_info.red_mask << sample) & 0x80000000UL) != 0)
          sample++;
        quantum_bits.red=(Quantum) (sample-shift.red);
        sample=shift.green;
        while (((bmp_info.green_mask << sample) & 0x80000000UL) != 0)
          sample++;
        quantum_bits.green=(Quantum) (sample-shift.green);
        sample=shift.blue;
        while (((bmp_info.blue_mask << sample) & 0x80000000UL) != 0)
          sample++;
        quantum_bits.blue=(Quantum) (sample-shift.blue);
        sample=shift.opacity;
        while (((bmp_info.alpha_mask << sample) & 0x80000000UL) != 0)
          sample++;
        quantum_bits.opacity=(Quantum) (sample-shift.opacity);
      }
    switch (bmp_info.bits_per_pixel)
    {
      case 1:
      {
        /*
          Convert bitmap scanline.
        */
        for (y=(ssize_t) image->rows-1; y >= 0; y--)
        {
          p=pixels+(image->rows-y-1)*bytes_per_line;
          q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
          if (q == (PixelPacket *) NULL)
            break;
          indexes=GetAuthenticIndexQueue(image);
          for (x=0; x < ((ssize_t) image->columns-7); x+=8)
          {
            for (bit=0; bit < 8; bit++)
            {
              index=(IndexPacket) (((*p) & (0x80 >> bit)) != 0 ? 0x01 : 0x00);
              indexes[x+bit]=index;
              *q++=image->colormap[(ssize_t) index];
            }
            p++;
          }
          if ((image->columns % 8) != 0)
            {
              for (bit=0; bit < (image->columns % 8); bit++)
              {
                index=(IndexPacket) (((*p) & (0x80 >> bit)) != 0 ? 0x01 : 0x00);
                indexes[x+bit]=index;
                *q++=image->colormap[(ssize_t) index];
              }
              p++;
            }
          if (SyncAuthenticPixels(image,exception) == MagickFalse)
            break;
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
      case 4:
      {
        /*
          Convert PseudoColor scanline.
        */
        for (y=(ssize_t) image->rows-1; y >= 0; y--)
        {
          p=pixels+(image->rows-y-1)*bytes_per_line;
          q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
          if (q == (PixelPacket *) NULL)
            break;
          indexes=GetAuthenticIndexQueue(image);
          for (x=0; x < ((ssize_t) image->columns-1); x+=2)
          {
            index=ConstrainColormapIndex(image,(*p >> 4) & 0x0f);
            indexes[x]=index;
            *q++=image->colormap[(ssize_t) index];
            index=ConstrainColormapIndex(image,*p & 0x0f);
            indexes[x+1]=index;
            *q++=image->colormap[(ssize_t) index];
            p++;
          }
          if ((image->columns % 2) != 0)
            {
              index=ConstrainColormapIndex(image,(*p >> 4) & 0xf);
              indexes[x]=index;
              *q++=image->colormap[(ssize_t) index];
              p++;
            }
          if (SyncAuthenticPixels(image,exception) == MagickFalse)
            break;
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
      case 8:
      {
        /*
          Convert PseudoColor scanline.
        */
        if ((bmp_info.compression == BI_RLE8) ||
            (bmp_info.compression == BI_RLE4))
          bytes_per_line=image->columns;
        for (y=(ssize_t) image->rows-1; y >= 0; y--)
        {
          p=pixels+(image->rows-y-1)*bytes_per_line;
          q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
          if (q == (PixelPacket *) NULL)
            break;
          indexes=GetAuthenticIndexQueue(image);
          for (x = (ssize_t)image->columns; x != 0; --x)
          {
            index=ConstrainColormapIndex(image,*p);
            *indexes++=index;
            *q=image->colormap[(ssize_t) index];
            p++;
            q++;
          }
          if (SyncAuthenticPixels(image,exception) == MagickFalse)
            break;
          offset=(MagickOffsetType) (image->rows-y-1);
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
      case 16:
      {
        size_t
          pixel;

        /*
          Convert bitfield encoded 16-bit PseudoColor scanline.
        */
        if (bmp_info.compression != BI_RGB &&
            bmp_info.compression != BI_BITFIELDS)
          {
            pixels=(unsigned char *) RelinquishMagickMemory(pixels);
            ThrowReaderException(CorruptImageError,
              "UnrecognizedImageCompression");
          }
        bytes_per_line=2*(image->columns+image->columns % 2);
        image->storage_class=DirectClass;
        for (y=(ssize_t) image->rows-1; y >= 0; y--)
        {
          p=pixels+(image->rows-y-1)*bytes_per_line;
          q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
          if (q == (PixelPacket *) NULL)
            break;
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            pixel=(size_t) (*p++);
            pixel|=(*p++) << 8;
            red=((pixel & bmp_info.red_mask) << shift.red) >> 16;
            if (quantum_bits.red == 5)
              red|=((red & 0xe000) >> 5);
            if (quantum_bits.red <= 8)
              red|=((red & 0xff00) >> 8);
            green=((pixel & bmp_info.green_mask) << shift.green) >> 16;
            if (quantum_bits.green == 5)
              green|=((green & 0xe000) >> 5);
            if (quantum_bits.green == 6)
              green|=((green & 0xc000) >> 6);
            if (quantum_bits.green <= 8)
              green|=((green & 0xff00) >> 8);
            blue=((pixel & bmp_info.blue_mask) << shift.blue) >> 16;
            if (quantum_bits.blue == 5)
              blue|=((blue & 0xe000) >> 5);
            if (quantum_bits.blue <= 8)
              blue|=((blue & 0xff00) >> 8);
            opacity=((pixel & bmp_info.alpha_mask) << shift.opacity) >> 16;
            if (quantum_bits.opacity <= 8)
              opacity|=((opacity & 0xff00) >> 8);
            q->red=ScaleShortToQuantum((unsigned short) red);
            q->green=ScaleShortToQuantum((unsigned short) green);
            q->blue=ScaleShortToQuantum((unsigned short) blue);
            SetOpacityPixelComponent(q,OpaqueOpacity);
            if (image->matte != MagickFalse)
              q->opacity=ScaleShortToQuantum((unsigned short) (65535-opacity));
            q++;
          }
          if (SyncAuthenticPixels(image,exception) == MagickFalse)
            break;
          offset=(MagickOffsetType) (image->rows-y-1);
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
      case 24:
      {
        /*
          Convert DirectColor scanline.
        */
        bytes_per_line=4*((image->columns*24+31)/32);
        for (y=(ssize_t) image->rows-1; y >= 0; y--)
        {
          p=pixels+(image->rows-y-1)*bytes_per_line;
          q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
          if (q == (PixelPacket *) NULL)
            break;
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            q->blue=ScaleCharToQuantum(*p++);
            q->green=ScaleCharToQuantum(*p++);
            q->red=ScaleCharToQuantum(*p++);
            SetOpacityPixelComponent(q,OpaqueOpacity);
            q++;
          }
          if (SyncAuthenticPixels(image,exception) == MagickFalse)
            break;
          offset=(MagickOffsetType) (image->rows-y-1);
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
      case 32:
      {
        /*
          Convert bitfield encoded DirectColor scanline.
        */
        if ((bmp_info.compression != BI_RGB) &&
            (bmp_info.compression != BI_BITFIELDS))
          {
            pixels=(unsigned char *) RelinquishMagickMemory(pixels);
            ThrowReaderException(CorruptImageError,
              "UnrecognizedImageCompression");
          }
        bytes_per_line=4*(image->columns);
        for (y=(ssize_t) image->rows-1; y >= 0; y--)
        {
          size_t
            pixel;

          p=pixels+(image->rows-y-1)*bytes_per_line;
          q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
          if (q == (PixelPacket *) NULL)
            break;
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            pixel=(size_t) (*p++);
            pixel|=(*p++ << 8);
            pixel|=(*p++ << 16);
            pixel|=(*p++ << 24);
            red=((pixel & bmp_info.red_mask) << shift.red) >> 16;
            if (quantum_bits.red == 8)
              red|=(red >> 8);
            green=((pixel & bmp_info.green_mask) << shift.green) >> 16;
            if (quantum_bits.green == 8)
              green|=(green >> 8);
            blue=((pixel & bmp_info.blue_mask) << shift.blue) >> 16;
            if (quantum_bits.blue == 8)
              blue|=(blue >> 8);
            opacity=((pixel & bmp_info.alpha_mask) << shift.opacity) >> 16;
            if (quantum_bits.opacity == 8)
              opacity|=(opacity >> 8);
            q->red=ScaleShortToQuantum((unsigned short) red);
            q->green=ScaleShortToQuantum((unsigned short) green);
            q->blue=ScaleShortToQuantum((unsigned short) blue);
            SetOpacityPixelComponent(q,OpaqueOpacity);
            if (image->matte != MagickFalse)
              q->opacity=ScaleShortToQuantum((unsigned short) (65535-opacity));
            q++;
          }
          if (SyncAuthenticPixels(image,exception) == MagickFalse)
            break;
          offset=(MagickOffsetType) (image->rows-y-1);
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,LoadImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
      default:
      {
        pixels=(unsigned char *) RelinquishMagickMemory(pixels);
        ThrowReaderException(CorruptImageError,"ImproperImageHeader");
      }
    }
    pixels=(unsigned char *) RelinquishMagickMemory(pixels);
    if (EOFBlob(image) != MagickFalse)
      {
        ThrowFileException(exception,CorruptImageError,"UnexpectedEndOfFile",
          image->filename);
        break;
      }
    if (bmp_info.height < 0)
      {
        Image
          *flipped_image;

        /*
          Correct image orientation.
        */
        flipped_image=FlipImage(image,exception);
        if (flipped_image != (Image *) NULL)
          {
            DuplicateBlob(flipped_image,image);
            image=DestroyImage(image);
            image=flipped_image;
          }
      }
    /*
      Proceed to next image.
    */
    if (image_info->number_scenes != 0)
      if (image->scene >= (image_info->scene+image_info->number_scenes-1))
        break;
    *magick='\0';
    if (bmp_info.ba_offset != 0)
      {
        offset=SeekBlob(image,(MagickOffsetType) bmp_info.ba_offset,SEEK_SET);
        if (offset < 0)
          ThrowReaderException(CorruptImageError,"ImproperImageHeader");
      }
    count=ReadBlob(image,2,magick);
    if ((count == 2) && (IsBMP(magick,2) != MagickFalse))
      {
        /*
          Acquire next image structure.
        */
        AcquireNextImage(image_info,image);
        if (GetNextImageInList(image) == (Image *) NULL)
          {
            image=DestroyImageList(image);
            return((Image *) NULL);
          }
        image=SyncNextImageInList(image);
        status=SetImageProgress(image,LoadImagesTag,TellBlob(image),
          GetBlobSize(image));
        if (status == MagickFalse)
          break;
      }
  } while (IsBMP(magick,2) != MagickFalse);
  (void) CloseBlob(image);
  return(GetFirstImageInList(image));
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e g i s t e r B M P I m a g e                                           %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  RegisterBMPImage() adds attributes for the BMP image format to
%  the list of supported formats.  The attributes include the image format
%  tag, a method to read and/or write the format, whether the format
%  supports the saving of more than one frame to the same file or blob,
%  whether the format supports native in-memory I/O, and a brief
%  description of the format.
%
%  The format of the RegisterBMPImage method is:
%
%      size_t RegisterBMPImage(void)
%
*/
ModuleExport size_t RegisterBMPImage(void)
{
  MagickInfo
    *entry;

  entry=SetMagickInfo("BMP");
  entry->decoder=(DecodeImageHandler *) ReadBMPImage;
  entry->encoder=(EncodeImageHandler *) WriteBMPImage;
  entry->magick=(IsImageFormatHandler *) IsBMP;
  entry->description=ConstantString("Microsoft Windows bitmap image");
  entry->module=ConstantString("BMP");
  entry->adjoin=MagickFalse;
  entry->seekable_stream=MagickTrue;
  (void) RegisterMagickInfo(entry);
  entry=SetMagickInfo("BMP2");
  entry->encoder=(EncodeImageHandler *) WriteBMPImage;
  entry->magick=(IsImageFormatHandler *) IsBMP;
  entry->description=ConstantString("Microsoft Windows bitmap image (V2)");
  entry->module=ConstantString("BMP");
  entry->adjoin=MagickFalse;
  entry->seekable_stream=MagickTrue;
  (void) RegisterMagickInfo(entry);
  entry=SetMagickInfo("BMP3");
  entry->encoder=(EncodeImageHandler *) WriteBMPImage;
  entry->magick=(IsImageFormatHandler *) IsBMP;
  entry->description=ConstantString("Microsoft Windows bitmap image (V3)");
  entry->module=ConstantString("BMP");
  entry->adjoin=MagickFalse;
  entry->seekable_stream=MagickTrue;
  (void) RegisterMagickInfo(entry);
  return(MagickImageCoderSignature);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   U n r e g i s t e r B M P I m a g e                                       %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  UnregisterBMPImage() removes format registrations made by the
%  BMP module from the list of supported formats.
%
%  The format of the UnregisterBMPImage method is:
%
%      UnregisterBMPImage(void)
%
*/
ModuleExport void UnregisterBMPImage(void)
{
  (void) UnregisterMagickInfo("BMP");
  (void) UnregisterMagickInfo("BMP2");
  (void) UnregisterMagickInfo("BMP3");
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   W r i t e B M P I m a g e                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  WriteBMPImage() writes an image in Microsoft Windows bitmap encoded
%  image format, version 3 for Windows or (if the image has a matte channel)
%  version 4.
%
%  The format of the WriteBMPImage method is:
%
%      MagickBooleanType WriteBMPImage(const ImageInfo *image_info,Image *image)
%
%  A description of each parameter follows.
%
%    o image_info: the image info.
%
%    o image:  The image.
%
*/
static MagickBooleanType WriteBMPImage(const ImageInfo *image_info,Image *image)
{
  BMPInfo
    bmp_info;

  const StringInfo
    *profile;

  ssize_t
    y;

  MagickBooleanType
    have_color_info,
    status;

  MagickOffsetType
    scene;

  register const IndexPacket
    *indexes;

  register const PixelPacket
    *p;

  register ssize_t
    i,
    x;

  register unsigned char
    *q;

  unsigned char
    *bmp_data,
    *pixels;

  size_t
    bytes_per_line,
    type;

  /*
    Open output image file.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  if (image->debug != MagickFalse)
    (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
  status=OpenBlob(image_info,image,WriteBinaryBlobMode,&image->exception);
  if (status == MagickFalse)
    return(status);
  type=4;
  if (LocaleCompare(image_info->magick,"BMP2") == 0)
    type=2;
  else
    if (LocaleCompare(image_info->magick,"BMP3") == 0)
      type=3;
  scene=0;
  do
  {
    /*
      Initialize BMP raster file header.
    */
    if (image->colorspace != RGBColorspace)
      (void) TransformImageColorspace(image,RGBColorspace);
    (void) ResetMagickMemory(&bmp_info,0,sizeof(bmp_info));
    bmp_info.file_size=14+12;
    if (type > 2)
      bmp_info.file_size+=28;
    bmp_info.offset_bits=bmp_info.file_size;
    bmp_info.compression=BI_RGB;
    if ((image->storage_class == PseudoClass) && (image->colors > 256))
      (void) SetImageStorageClass(image,DirectClass);
    if (image->storage_class != DirectClass)
      {
        /*
          Colormapped BMP raster.
        */
        bmp_info.bits_per_pixel=8;
        if (image->colors <= 2)
          bmp_info.bits_per_pixel=1;
        else
          if (image->colors <= 16)
            bmp_info.bits_per_pixel=4;
          else
            if (image->colors <= 256)
              bmp_info.bits_per_pixel=8;
        if (image_info->compression == RLECompression)
          bmp_info.bits_per_pixel=8;
        bmp_info.number_colors=1U << bmp_info.bits_per_pixel;
        if (image->matte != MagickFalse)
          (void) SetImageStorageClass(image,DirectClass);
        else
          if ((size_t) bmp_info.number_colors < image->colors)
            (void) SetImageStorageClass(image,DirectClass);
          else
            {
              bmp_info.file_size+=3*(1UL << bmp_info.bits_per_pixel);
              bmp_info.offset_bits+=3*(1UL << bmp_info.bits_per_pixel);
              if (type > 2)
                {
                  bmp_info.file_size+=(1UL << bmp_info.bits_per_pixel);
                  bmp_info.offset_bits+=(1UL << bmp_info.bits_per_pixel);
                }
            }
      }
    if (image->storage_class == DirectClass)
      {
        /*
          Full color BMP raster.
        */
        bmp_info.number_colors=0;
        bmp_info.bits_per_pixel=(unsigned short)
          ((type > 3) && (image->matte != MagickFalse) ? 32 : 24);
        bmp_info.compression=(unsigned int) ((type > 3) &&
          (image->matte != MagickFalse) ?  BI_BITFIELDS : BI_RGB);
      }
    bytes_per_line=4*((image->columns*bmp_info.bits_per_pixel+31)/32);
    bmp_info.ba_offset=0;
    profile=GetImageProfile(image,"icc");
    have_color_info=(image->rendering_intent != UndefinedIntent) ||
      (profile != (StringInfo *) NULL) || (image->gamma != 0.0) ?  MagickTrue :
      MagickFalse;
    if (type == 2)
      bmp_info.size=12;
    else
      if ((type == 3) || ((image->matte == MagickFalse) &&
          (have_color_info == MagickFalse)))
        {
          type=3;
          bmp_info.size=40;
        }
      else
        {
          int
            extra_size;

          bmp_info.size=108;
          extra_size=68;
          if ((image->rendering_intent != UndefinedIntent) ||
              (profile != (StringInfo *) NULL))
            {
              bmp_info.size=124;
              extra_size+=16;
            }
          bmp_info.file_size+=extra_size;
          bmp_info.offset_bits+=extra_size;
        }
    bmp_info.width=(ssize_t) image->columns;
    bmp_info.height=(ssize_t) image->rows;
    bmp_info.planes=1;
    bmp_info.image_size=(unsigned int) (bytes_per_line*image->rows);
    bmp_info.file_size+=bmp_info.image_size;
    bmp_info.x_pixels=75*39;
    bmp_info.y_pixels=75*39;
    switch (image->units)
    {
      case UndefinedResolution:
      case PixelsPerInchResolution:
      {
        bmp_info.x_pixels=(unsigned int) (100.0*image->x_resolution/2.54);
        bmp_info.y_pixels=(unsigned int) (100.0*image->y_resolution/2.54);
        break;
      }
      case PixelsPerCentimeterResolution:
      {
        bmp_info.x_pixels=(unsigned int) (100.0*image->x_resolution);
        bmp_info.y_pixels=(unsigned int) (100.0*image->y_resolution);
        break;
      }
    }
    bmp_info.colors_important=bmp_info.number_colors;
    /*
      Convert MIFF to BMP raster pixels.
    */
    pixels=(unsigned char *) AcquireQuantumMemory((size_t) bmp_info.image_size,
      sizeof(*pixels));
    if (pixels == (unsigned char *) NULL)
      ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
    (void) ResetMagickMemory(pixels,0,(size_t) bmp_info.image_size);
    switch (bmp_info.bits_per_pixel)
    {
      case 1:
      {
        size_t
          bit,
          byte;

        /*
          Convert PseudoClass image to a BMP monochrome image.
        */
        for (y=0; y < (ssize_t) image->rows; y++)
        {
          p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
          if (p == (const PixelPacket *) NULL)
            break;
          indexes=GetVirtualIndexQueue(image);
          q=pixels+(image->rows-y-1)*bytes_per_line;
          bit=0;
          byte=0;
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            byte<<=1;
            byte|=indexes[x] != 0 ? 0x01 : 0x00;
            bit++;
            if (bit == 8)
              {
                *q++=(unsigned char) byte;
                bit=0;
                byte=0;
              }
           }
           if (bit != 0)
             {
               *q++=(unsigned char) (byte << (8-bit));
               x++;
             }
          for (x=(ssize_t) (image->columns+7)/8; x < (ssize_t) bytes_per_line; x++)
            *q++=0x00;
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
      case 4:
      {
        size_t
          nibble,
          byte;

        /*
          Convert PseudoClass image to a BMP monochrome image.
        */
        for (y=0; y < (ssize_t) image->rows; y++)
        {
          p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
          if (p == (const PixelPacket *) NULL)
            break;
          indexes=GetVirtualIndexQueue(image);
          q=pixels+(image->rows-y-1)*bytes_per_line;
          nibble=0;
          byte=0;
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            byte<<=4;
            byte|=((size_t) indexes[x] & 0x0f);
            nibble++;
            if (nibble == 2)
              {
                *q++=(unsigned char) byte;
                nibble=0;
                byte=0;
              }
           }
         if (nibble != 0)
           {
             *q++=(unsigned char) (byte << 4);
             x++;
           }
          for (x=(ssize_t) (image->columns+1)/2; x < (ssize_t) bytes_per_line; x++)
            *q++=0x00;
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
      case 8:
      {
        /*
          Convert PseudoClass packet to BMP pixel.
        */
        for (y=0; y < (ssize_t) image->rows; y++)
        {
          p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
          if (p == (const PixelPacket *) NULL)
            break;
          indexes=GetVirtualIndexQueue(image);
          q=pixels+(image->rows-y-1)*bytes_per_line;
          for (x=0; x < (ssize_t) image->columns; x++)
            *q++=(unsigned char) indexes[x];
          for ( ; x < (ssize_t) bytes_per_line; x++)
            *q++=0x00;
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
      case 24:
      {
        /*
          Convert DirectClass packet to BMP BGR888.
        */
        for (y=0; y < (ssize_t) image->rows; y++)
        {
          p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
          if (p == (const PixelPacket *) NULL)
            break;
          q=pixels+(image->rows-y-1)*bytes_per_line;
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            *q++=ScaleQuantumToChar(GetBluePixelComponent(p));
            *q++=ScaleQuantumToChar(GetGreenPixelComponent(p));
            *q++=ScaleQuantumToChar(GetRedPixelComponent(p));
            p++;
          }
          for (x=3L*(ssize_t) image->columns; x < (ssize_t) bytes_per_line; x++)
            *q++=0x00;
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
      case 32:
      {
        /*
          Convert DirectClass packet to ARGB8888 pixel.
        */
        for (y=0; y < (ssize_t) image->rows; y++)
        {
          p=GetVirtualPixels(image,0,y,image->columns,1,&image->exception);
          if (p == (const PixelPacket *) NULL)
            break;
          q=pixels+(image->rows-y-1)*bytes_per_line;
          for (x=0; x < (ssize_t) image->columns; x++)
          {
            *q++=ScaleQuantumToChar(GetBluePixelComponent(p));
            *q++=ScaleQuantumToChar(GetGreenPixelComponent(p));
            *q++=ScaleQuantumToChar(GetRedPixelComponent(p));
            *q++=ScaleQuantumToChar(QuantumRange-GetOpacityPixelComponent(p));
            p++;
          }
          if (image->previous == (Image *) NULL)
            {
              status=SetImageProgress(image,SaveImageTag,(MagickOffsetType) y,
                image->rows);
              if (status == MagickFalse)
                break;
            }
        }
        break;
      }
    }
    if ((type > 2) && (bmp_info.bits_per_pixel == 8))
      if (image_info->compression != NoCompression)
        {
          size_t
            length;

          /*
            Convert run-length encoded raster pixels.
          */
          length=(size_t) (2*(bytes_per_line+2)*(image->rows+2)+2);
          bmp_data=(unsigned char *) NULL;
          if (~length >= bytes_per_line)
            bmp_data=(unsigned char *) AcquireQuantumMemory(length+
              bytes_per_line,sizeof(*bmp_data));
          if (bmp_data == (unsigned char *) NULL)
            {
              pixels=(unsigned char *) RelinquishMagickMemory(pixels);
              ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
            }
          bmp_info.file_size-=bmp_info.image_size;
          bmp_info.image_size=(unsigned int) EncodeImage(image,bytes_per_line,
            pixels,bmp_data);
          bmp_info.file_size+=bmp_info.image_size;
          pixels=(unsigned char *) RelinquishMagickMemory(pixels);
          pixels=bmp_data;
          bmp_info.compression=BI_RLE8;
        }
    /*
      Write BMP for Windows, all versions, 14-byte header.
    */
    if (image->debug != MagickFalse)
      {
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "   Writing BMP version %.20g datastream",(double) type);
        if (image->storage_class == DirectClass)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "   Storage class=DirectClass");
        else
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "   Storage class=PseudoClass");
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "   Image depth=%.20g",(double) image->depth);
        if (image->matte != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "   Matte=True");
        else
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "   Matte=MagickFalse");
        (void) LogMagickEvent(CoderEvent,GetMagickModule(),
          "   BMP bits_per_pixel=%.20g",(double) bmp_info.bits_per_pixel);
        switch ((int) bmp_info.compression)
        {
           case BI_RGB:
           {
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "   Compression=BI_RGB");
             break;
           }
           case BI_RLE8:
           {
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "   Compression=BI_RLE8");
             break;
           }
           case BI_BITFIELDS:
           {
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "   Compression=BI_BITFIELDS");
             break;
           }
           default:
           {
             (void) LogMagickEvent(CoderEvent,GetMagickModule(),
               "   Compression=UNKNOWN (%u)",bmp_info.compression);
             break;
           }
        }
        if (bmp_info.number_colors == 0)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "   Number_colors=unspecified");
        else
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "   Number_colors=%u",bmp_info.number_colors);
      }
    (void) WriteBlob(image,2,(unsigned char *) "BM");
    (void) WriteBlobLSBLong(image,bmp_info.file_size);
    (void) WriteBlobLSBLong(image,bmp_info.ba_offset);  /* always 0 */
    (void) WriteBlobLSBLong(image,bmp_info.offset_bits);
    if (type == 2)
      {
        /*
          Write 12-byte version 2 bitmap header.
        */
        (void) WriteBlobLSBLong(image,bmp_info.size);
        (void) WriteBlobLSBShort(image,(unsigned short) bmp_info.width);
        (void) WriteBlobLSBShort(image,(unsigned short) bmp_info.height);
        (void) WriteBlobLSBShort(image,bmp_info.planes);
        (void) WriteBlobLSBShort(image,bmp_info.bits_per_pixel);
      }
    else
      {
        /*
          Write 40-byte version 3+ bitmap header.
        */
        (void) WriteBlobLSBLong(image,bmp_info.size);
        (void) WriteBlobLSBLong(image,(unsigned int) bmp_info.width);
        (void) WriteBlobLSBLong(image,(unsigned int) bmp_info.height);
        (void) WriteBlobLSBShort(image,bmp_info.planes);
        (void) WriteBlobLSBShort(image,bmp_info.bits_per_pixel);
        (void) WriteBlobLSBLong(image,bmp_info.compression);
        (void) WriteBlobLSBLong(image,bmp_info.image_size);
        (void) WriteBlobLSBLong(image,bmp_info.x_pixels);
        (void) WriteBlobLSBLong(image,bmp_info.y_pixels);
        (void) WriteBlobLSBLong(image,bmp_info.number_colors);
        (void) WriteBlobLSBLong(image,bmp_info.colors_important);
      }
    if ((type > 3) && ((image->matte != MagickFalse) ||
        (have_color_info != MagickFalse)))
      {
        /*
          Write the rest of the 108-byte BMP Version 4 header.
        */
        (void) WriteBlobLSBLong(image,0x00ff0000U);  /* Red mask */
        (void) WriteBlobLSBLong(image,0x0000ff00U);  /* Green mask */
        (void) WriteBlobLSBLong(image,0x000000ffU);  /* Blue mask */
        (void) WriteBlobLSBLong(image,0xff000000U);  /* Alpha mask */
        (void) WriteBlobLSBLong(image,0x00000001U);  /* CSType==Calib. RGB */
        (void) WriteBlobLSBLong(image,(unsigned int)
          image->chromaticity.red_primary.x*0x3ffffff);
        (void) WriteBlobLSBLong(image,(unsigned int)
          image->chromaticity.red_primary.y*0x3ffffff);
        (void) WriteBlobLSBLong(image,(unsigned int)
          (1.000f-(image->chromaticity.red_primary.x+
          image->chromaticity.red_primary.y)*0x3ffffff));
        (void) WriteBlobLSBLong(image,(unsigned int)
          image->chromaticity.green_primary.x*0x3ffffff);
        (void) WriteBlobLSBLong(image,(unsigned int)
          image->chromaticity.green_primary.y*0x3ffffff);
        (void) WriteBlobLSBLong(image,(unsigned int)
          (1.000f-(image->chromaticity.green_primary.x+
          image->chromaticity.green_primary.y)*0x3ffffff));
        (void) WriteBlobLSBLong(image,(unsigned int)
          image->chromaticity.blue_primary.x*0x3ffffff);
        (void) WriteBlobLSBLong(image,(unsigned int)
          image->chromaticity.blue_primary.y*0x3ffffff);
        (void) WriteBlobLSBLong(image,(unsigned int)
          (1.000f-(image->chromaticity.blue_primary.x+
          image->chromaticity.blue_primary.y)*0x3ffffff));
        (void) WriteBlobLSBLong(image,(unsigned int)
          bmp_info.gamma_scale.x*0xffff);
        (void) WriteBlobLSBLong(image,(unsigned int)
          bmp_info.gamma_scale.y*0xffff);
        (void) WriteBlobLSBLong(image,(unsigned int)
          bmp_info.gamma_scale.z*0xffff);
        if ((image->rendering_intent != UndefinedIntent) ||
            (profile != (StringInfo *) NULL))
          {
            ssize_t
              intent;

            switch ((int) image->rendering_intent)
            {
              case SaturationIntent:
              {
                intent=LCS_GM_BUSINESS;
                break;
              }
              case RelativeIntent:
              {
                intent=LCS_GM_GRAPHICS;
                break;
              }
              case PerceptualIntent:
              {
                intent=LCS_GM_IMAGES;
                break;
              }
              case AbsoluteIntent:
              {
                intent=LCS_GM_ABS_COLORIMETRIC;
                break;
              }
              default:
              {
                intent=0;
                break;
              }
            }
            (void) WriteBlobLSBLong(image,(unsigned int) intent);
            (void) WriteBlobLSBLong(image,0x00);  /* dummy profile data */
            (void) WriteBlobLSBLong(image,0x00);  /* dummy profile length */
            (void) WriteBlobLSBLong(image,0x00);  /* reserved */
          }
      }
    if (image->storage_class == PseudoClass)
      {
        unsigned char
          *bmp_colormap;

        /*
          Dump colormap to file.
        */
        if (image->debug != MagickFalse)
          (void) LogMagickEvent(CoderEvent,GetMagickModule(),
            "  Colormap: %.20g entries",(double) image->colors);
        bmp_colormap=(unsigned char *) AcquireQuantumMemory((size_t) (1UL <<
          bmp_info.bits_per_pixel),4*sizeof(*bmp_colormap));
        if (bmp_colormap == (unsigned char *) NULL)
          ThrowWriterException(ResourceLimitError,"MemoryAllocationFailed");
        q=bmp_colormap;
        for (i=0; i < (ssize_t) MagickMin((ssize_t) image->colors,(ssize_t) bmp_info.number_colors); i++)
        {
          *q++=ScaleQuantumToChar(image->colormap[i].blue);
          *q++=ScaleQuantumToChar(image->colormap[i].green);
          *q++=ScaleQuantumToChar(image->colormap[i].red);
          if (type > 2)
            *q++=(unsigned char) 0x0;
        }
        for ( ; i < (ssize_t) (1UL << bmp_info.bits_per_pixel); i++)
        {
          *q++=(unsigned char) 0x00;
          *q++=(unsigned char) 0x00;
          *q++=(unsigned char) 0x00;
          if (type > 2)
            *q++=(unsigned char) 0x00;
        }
        if (type <= 2)
          (void) WriteBlob(image,(size_t) (3*(1L << bmp_info.bits_per_pixel)),
            bmp_colormap);
        else
          (void) WriteBlob(image,(size_t) (4*(1L << bmp_info.bits_per_pixel)),
            bmp_colormap);
        bmp_colormap=(unsigned char *) RelinquishMagickMemory(bmp_colormap);
      }
    if (image->debug != MagickFalse)
      (void) LogMagickEvent(CoderEvent,GetMagickModule(),
        "  Pixels:  %u bytes",bmp_info.image_size);
    (void) WriteBlob(image,(size_t) bmp_info.image_size,pixels);
    pixels=(unsigned char *) RelinquishMagickMemory(pixels);
    if (GetNextImageInList(image) == (Image *) NULL)
      break;
    image=SyncNextImageInList(image);
    status=SetImageProgress(image,SaveImagesTag,scene++,
      GetImageListLength(image));
    if (status == MagickFalse)
      break;
  } while (image_info->adjoin != MagickFalse);
  (void) CloseBlob(image);
  return(MagickTrue);
}